U.S. patent number 7,766,970 [Application Number 10/862,821] was granted by the patent office on 2010-08-03 for method and apparatus for wrist arthroplasty.
This patent grant is currently assigned to Biomet Manufacturing Corp.. Invention is credited to Brian K. Berelsman, Thomas J. Graham, Andrew K. Palmer, Jason M. Shultz, Kevin T. Stone, James W. Strickland.
United States Patent |
7,766,970 |
Shultz , et al. |
August 3, 2010 |
**Please see images for:
( Certificate of Correction ) ** |
Method and apparatus for wrist arthroplasty
Abstract
A prosthetic wrist having at least one of a radial insert, which
is configured to be fixed to a radius of a patient, a carpal
implant and a wrist bearing component. The carpal implant includes
a body and a pair of flanges, each of which being skewed to the
axis of the body in a manner that permits them to abut the ulnar
side of the hamate bone and the radial side of the distal portion
of the carpal bone complex, respectively. The radial insert may be
provided with a plurality of modular portions to allow for
selection and customization of an implant.
Inventors: |
Shultz; Jason M. (Warsaw,
IN), Palmer; Andrew K. (Cazenovia, NY), Stone; Kevin
T. (Winona Lake, IN), Graham; Thomas J. (Cockeysville,
MD), Berelsman; Brian K. (Warsaw, IN), Strickland; James
W. (Zionsville, IN) |
Assignee: |
Biomet Manufacturing Corp.
(Warsaw, IN)
|
Family
ID: |
46204621 |
Appl.
No.: |
10/862,821 |
Filed: |
June 7, 2004 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050004675 A1 |
Jan 6, 2005 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10279240 |
Jun 8, 2004 |
6746486 |
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Current U.S.
Class: |
623/21.14;
623/21.12 |
Current CPC
Class: |
A61F
2/4261 (20130101); A61F 2220/0025 (20130101); A61F
2002/30448 (20130101); A61F 2/0095 (20130101); A61F
2230/0028 (20130101); A61F 2002/30535 (20130101); A61F
2230/005 (20130101); A61F 2002/30884 (20130101); A61F
2002/30179 (20130101); A61F 2310/00029 (20130101); A61F
2310/00023 (20130101); A61F 2002/30841 (20130101); A61F
2002/30616 (20130101); A61F 2310/00161 (20130101); A61F
2002/30578 (20130101); A61F 2220/005 (20130101); A61F
2002/30538 (20130101); A61F 2002/30787 (20130101); A61F
2002/30614 (20130101); A61F 2250/0058 (20130101); A61F
2002/3065 (20130101); A61F 2002/30171 (20130101); A61F
2002/30662 (20130101); A61F 2230/0058 (20130101); A61F
2002/30654 (20130101); A61F 2002/30383 (20130101); A61F
2002/3069 (20130101); A61F 2220/0033 (20130101); A61F
2002/30604 (20130101); A61F 2002/4264 (20130101); A61F
2250/0006 (20130101); A61B 17/80 (20130101); A61F
2002/30507 (20130101); A61F 2002/30354 (20130101); A61F
2310/00179 (20130101) |
Current International
Class: |
A61F
2/42 (20060101) |
Field of
Search: |
;623/21.11,21.12,21.13,21.14 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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100 43 107 |
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Sep 2002 |
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DE |
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10237016 |
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Feb 2004 |
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DE |
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0 034 192 |
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Aug 1981 |
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EP |
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GB2269752 |
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Feb 1994 |
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EP |
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2660856 |
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Oct 1991 |
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FR |
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WO 92/00709 |
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Jan 1992 |
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WO |
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WO 9731593 |
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Sep 1997 |
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WO |
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WO 2006/048520 |
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May 2006 |
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WO |
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WO-2007047230 |
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Apr 2007 |
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WO |
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Other References
Universal Total Wrist Implant System at
www.visitkmi.com/totwrist.html. cited by other .
European Search Report for EP 07 25 3509 mailed Jan. 14, 2008.
cited by other.
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Primary Examiner: Willse; David H
Assistant Examiner: Blanco; Javier G
Attorney, Agent or Firm: Harness, Dickey
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent
application Ser. No. 10/279,240 filed on Oct. 24, 2002, which is
now U.S. Pat. No. 6,746,486 issued on Jun. 8, 2004. The disclosure
of the above application is incorporated herein by reference.
Claims
What is claimed is:
1. A method of performing a procedure relative to a radius and a
carpal complex, comprising: forming an incision relative to the
wrist; determining an arthroplasty to be performed for the wrist
arthroplasty; selecting a stem member; selecting a distal radial
segment that includes a carpal engaging portion that defines a
first recess and an ulnar engaging portion that defines a second
recess that is distinct from the first recess; interconnecting the
selected stem member and the selected distal radial segment;
positioning the stem member within the radius; positioning a
selected volume of the carpal complex directly within the first
recess of the carpal engaging portion such that the distal radial
segment is directly engaged with the carpal complex; positioning a
selected portion of the natural ulna directly within the second
recess of the ulnar engaging portion.
2. The method of claim 1, wherein interconnecting the selected stem
member and the selected distal radial segment further comprises:
interconnecting a male connecting member of the selected stem
member with a female connecting member of the selected distal
radial segment.
3. The method of claim 2, wherein interconnecting a male connecting
member with a female connecting member includes threading an
externally threaded male member into an internally threaded female
bore defined by the distal radial segment.
4. The method of claim 1, wherein selecting the distal radial
segment includes selecting at least one of a height, a width, a
depth, an articulating surface, a bone holding segment, or
combinations thereof of the distal radial segment.
5. The method of claim 4, further comprising: evaluating a
plurality of the distal radial segments wherein each of the
plurality of distal radial segments includes at least one of a
different height, width, depth, articulating surface,
configuration, ulna bearing segment, or combinations thereof;
wherein each of the plurality of the distal radial segments is
separately interconnected with the stem member.
6. The method of claim 5, further comprising: resecting a portion
of the radius; and selecting the distal radial segment to include a
height to accommodate the resected portion of the radius.
7. The method of claim 1, further comprising: allowing movement of
the distal radial segment to articulate with all of the selected
volume of the carpal complex within the carpal engaging portion and
the ulna.
8. The method of claim 1, wherein selecting a stem member includes
selecting one stem member from a plurality of stem members each
extending from a first end operable to be positioned within the
radius and a second end defining a male attachment portion; wherein
selecting a distal radial segment includes selecting a member
extending from a first end defining the carpal engaging portion
defining the first recess and a second end defining a female
engagement portion; wherein interconnecting the selected stem
member and the selected distal radial segment includes fixing
together the selected stem member and the selected distal radial
segment for positioning within the radius.
9. The method of claim 1, wherein selecting a distal radial segment
includes: selecting an exterior wall of the distal radial segment
to be substantially rectangular; wherein the carpal engaging
portion defining the first and second recesses within the distal
radial segment includes defining the first and second recesses
within the rectangular external walls.
10. The method of claim 1 wherein the first recess has a carpal
engaging surface defined by a radius taken from a first axis that
extends substantially in the anterior/posterior direction.
11. The method of claim 10 wherein the second recess has an ulnar
engaging surface defined by a radius taken from a second axis that
is non-intersecting with the first axis.
12. The method of claim 11 wherein the second axis is substantially
parallel to a longitudinal axis of the selected stem member.
13. The method of claim 1 wherein the second axis extends
substantially in the proximal/distal direction.
14. The method of claim 1 wherein the first and second recesses
intersect within the distal radial segment.
15. A method of performing a procedure relative to a radius and a
carpal complex, comprising: forming an incision relative to the
wrist; determining an arthroplasty to be performed for the wrist
arthroplasty; selecting a stem member from a plurality of stem
members each including a stem connection region; selecting a distal
radial segment from a plurality of distal radial segments, each of
the plurality of distal radial segments including: a body portion
to replace a portion of a radius resected during the determined
arthroplasty, a carpal engaging portion extending from the body
portion having a first and a second internal wall, the first
internal wall defining a carpal receiving recess extending into the
carpal engaging portion to receive at least a portion of the carpal
complex, the second internal wall defining an ulnar receiving
recess to receive at least a portion of an ulna, and a distal
radial segment connection region; connecting the selected stem
member and the selected distal radial segment by fixing together
the stem connection region and the distal radial segment connection
region; positioning the connected stem member into the radius; and
positioning a selected volume of the carpal complex directly within
the carpal receiving recess of the carpal engaging portion to
capture and contact the selected volume of the carpal complex with
the distal radial segment, including positioning the selected
volume of the carpal complex within the recess defined within a
substantially rectangular external wall defined by the carpal
engaging portion and positioning a selected portion of the natural
ulna directly within the ulnar receiving recess.
16. The method of claim 15, wherein including a stem connection
region includes providing a male connecting member; wherein
including a distal radial segment connection region of the selected
stem member includes providing a female connecting depression in
the distal radial segment opposed to the carpal receiving
recess.
17. The method of claim 16, wherein connecting the selected stem
member includes connecting a separate selected stem member and a
separate selected distal radial segment after selecting a separate
and distinct stem member and a separate and distinct distal radial
segment.
18. The method of claim 15, wherein selecting a distal radial
segment from a plurality of distal radial segments includes:
resecting a selected portion of the radius; determining an
anatomically correct radius replacement portion based at least on
the resected portion of the radius; and selecting a dimension of
the body to replace the determined anatomically correct radius
replacement portion.
19. The method of claim 18, wherein determining an anatomically
correct radius replacement portion includes: determining a length
of the selected portion of the radius that is resected; and
selecting a height of the body portion to substantially equal the
length of the selected portion of the radius that is resected.
20. The method of claim 19, further comprising: positioning an
exterior surface of the body portion to contact the resected
radius; wherein positioning the connected stem member into the
radius includes positioning the stem member into an intramedullary
canal of the radius.
21. The method of claim 15 wherein the first internal wall has a
carpal engaging surface defined by a radius taken from a first axis
that extends substantially in the anterior/posterior direction.
22. The method of claim 21 wherein the second internal wall has an
ulnar engaging surface defined by a radius taken from a second axis
that is non-intersecting with the first axis.
23. The method of claim 22 wherein the second axis is substantially
parallel to a longitudinal axis of the selected stem member.
24. The method of claim 22 wherein the second axis extends
substantially in the proximal/distal direction.
25. The method of claim 15 wherein the first and second internal
walls intersect within the distal radial segment.
26. A method of performing a procedure relative to a radius and a
carpal complex of a wrist, comprising: forming an incision relative
to the wrist; providing a distal radial segment having a body that
has a first internal wall that defines a first recess, and a second
internal wall that defines a second recess, the first recess having
a carpal engaging surface defined by a radius taken from a first
axis that extends substantially in an anterior/posterior direction,
the second recess having an ulnar engaging surface defined by a
radius taken from a second axis that extends substantially in the
proximal/distal direction; providing a stem member; interconnecting
the stem member with the distal radial segment; positioning the
stem member within the radius; positioning a selected volume of the
carpal complex directly within the first recess such that the
carpal complex engages the first internal wall; and positioning a
selected portion of the natural ulna directly within the second
recess such that the ulna engages the second internal wall.
Description
FIELD
The present invention generally relates to prosthetic implants and
more particularly to a prosthetic wrist implants.
BACKGROUND
With reference to FIG. 1 of the drawings, the dorsal side of the
bone structure of a patient's left hand and wrist is illustrated in
conjunction with the radius 2 and the ulna 4. The bone structure
includes a carpal bone complex 6 having a scaphoid 8, a lunate 10,
a triquetrum 12, a pisiform 14, a trapezium 16, a trapezoid 18, a
capitate 20 and a hamate 22. It will be appreciated that the
scaphoid 8 and the lunate 10 bones articulate with the radius 2
during the movement of the wrist.
In a variety of wrist disorders, patients may experience
discomfort, pain and difficulty in moving the wrist. Prior surgical
treatment of this condition involved fusion to inhibit movement of
the scaphoid 8 and the lunate 10 bones relative to the radius to
thereby alleviate pain in the patient's wrist. This procedure,
however, leaves the patient without motion in their wrist and
thereby severely restricts the use of their wrist. Prosthetic wrist
implants have been developed to provide a pair of artificial
bearing surfaces for the wrist. Several of the prior wrist implants
have suffered from drawbacks including limited range of motion and
excessive bone resection. Others still provide proper motion only
when aligned in an extremely precise manner relative to the carpal
bone complex 6. While various jigs and fixtures may be employed to
aid in the locating and forming of a hole in the distal portion of
the carpal bone complex 6 for receiving a carpal implant, these
devices typically do not completely eliminate the possibility of
error in the alignment and forming of the hole.
Accordingly, there remains a need in the art for an improved
prosthetic wrist implant that provides improved support and
strength for the distal portion of the carpal bone complex 6 and
which has a bearing surface whose orientation is changeable after
implantation to provide the implanted prosthetic wrist with a range
of motion that mimics the range of motion of a natural wrist.
SUMMARY
An implant for a wrist arthroplasty, such as a total or
hemi-arthroplasty, are disclosed. Various embodiments include
providing a hemi-arthroplasty included for either replacing the
distal portions of the radius, ulna or both to articulate with
natural portions of the carpal bone complex. Also, a
hemi-arthroplasty that includes replacing portions of only the
carpal bone complex. Alternatively, an arthroplasty may occur
regarding the radius or ulna bones and the carpal bones to provide
a substantially complete wrist arthroplasty. In addition, both the
carpal bone complex prosthetic and the radius and ulna prosthetic
may include substantially modular portions such that selections may
be made during an operative procedure to assist in providing a
substantially best fit or customized implant for a selected
patient. In addition, various portions of the prosthetic may
include parts to replace complete bones of the carpal bone complex
or other anatomical portions to assist in providing a substantially
natural articulation and range of motion of the wrist after the
procedure.
According to various embodiments, a modular prosthetic for
placement in a wrist relative to a radius is disclosed. A distal
radial assembly may include a stem portion operable to be
positioned relative to a portion of the radius and a distal radial
segment operable to be interconnected with the stem portion during
an operative procedure. The stem portion and the distal radial
segment are provided to be interconnected to substantially form a
portion of a radial articulation with a carpal complex.
According to various embodiments, a modular prosthetic for
placement in a wrist is disclosed. A distal radial assembly
including a stem portion operable to be positioned within a portion
of a radius and a distal radial segment operable to be
interconnected with the stem portion during an operative procedure.
The modular prosthetic may also include a carpal implant operable
to be interconnected with a portion of the wrist to articulate with
the distal radial implant. The stem portion and the distal radial
segment are provided to be interconnected to substantially form a
portion of a radial articulation with a carpal complex.
According to various embodiments, a kit for performing an
arthroplasty relative to the wrist joint including the radius and
the carpal complex is disclosed. A stem member operable to be
positioned relative to the radius having a stem connection portion
may be provided. A distal radial segment may also be included
having a segment connecting portion operable to be associated with
the stem member. A carpal implant may be provided to be associated
with the carpal complex. Also, a bearing member may be disposable
between the distal radial segment and the carpal complex implant.
At least two of the stem member, the distal radial segment, the
carpal complex implant; and the bearing member are associated to
perform the arthroplasty.
According to various embodiments a method of performing a wrist
arthroplasty relative to a radius and a carpal complex. The method
includes forming an incision relative to the wrist and determining
an arthroplasty to be performed for the wrist arthroplasty. Also a
stem member and a distal radial segment may be selected. The
selected stem member and the distal radial segment may be
interconnected. Each of the members may be positioned in the
anatomy and the stem member may be positioned relative to the
radius.
Further areas of applicability of the present invention will become
apparent from the detailed description provided hereinafter. It
should be understood that the detailed description and specific
examples, while indicating the various embodiment of the invention,
are intended for purposes of illustration only and are not intended
to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional advantages and features of the present invention will
become apparent from the subsequent description and the appended
claims, taken in conjunction with the accompanying drawings,
wherein:
FIG. 1 is a view of the dorsal side of a patient's left hand and
wrist illustrating the bone structure of the hand and wrist in
conjunction with the radius and the ulna;
FIG. 2 is a view of the dorsal side of a patient's left hand and
wrist illustrating the implantation of a prosthetic wrist implant
constructed in accordance with the teachings of the present
invention;
FIG. 3 is an exploded view of a prosthetic wrist constructed in
accordance with the teachings of the present invention;
FIG. 4 is a perspective view of a portion of the prosthetic wrist
of FIG. 2 illustrating the carpal implant in greater detail;
FIG. 5 is a side view of a portion of the prosthetic wrist of FIG.
2 illustrating the wrist bearing component in the coronal
plane;
FIG. 6 is a side view of a portion of the prosthetic wrist of FIG.
2 illustrating the wrist bearing component in the sagittal
plane;
FIG. 7 is an exploded perspective view of a prosthetic wrist
similar to that of FIG. 2 but additionally including an alignment
mechanism for radially fixing the wrist bearing component relative
to the carpal implant;
FIG. 8 is an exploded view in partial section of a prosthetic wrist
constructed in accordance with the teachings of a second embodiment
of the present invention;
FIG. 9 is a view of a kit that utilizes the prosthetic wrist of
FIG. 8;
FIG. 10 is a side elevation view of a carpal implant constructed in
accordance with the teachings of a third embodiment of the present
invention;
FIG. 11 is a side elevation view of a carpal implant constructed in
accordance with the teachings of a fourth embodiment of the present
invention;
FIG. 12 is a side elevation view of a carpal implant constructed in
accordance with the teachings of a fifth embodiment of the present
invention;
FIG. 13 is an exploded front elevation view of a portion of a
prosthetic wrist constructed in accordance with the teachings of a
sixth embodiment of the present invention;
FIG. 14 is a side elevation view of a portion of the prosthetic
wrist of FIG. 13;
FIG. 15 is an exploded side elevation view of a prosthetic wrist
constructed in accordance with the teachings of a seventh
embodiment of the present invention;
FIG. 16 is an exploded side elevation view of a prosthetic wrist
constructed in accordance with the teachings of an eighth
embodiment of the present invention;
FIG. 17 is an exploded perspective view of a prosthetic wrist
constructed in accordance with the teachings of a ninth embodiment
of the present invention;
FIG. 18 is an exploded side elevation view of the prosthetic wrist
of FIG. 17;
FIG. 19 is an exploded perspective view of a prosthetic wrist
constructed in accordance with the teachings of a tenth embodiment
of the present invention;
FIG. 20 is an exploded side elevation view of the prosthetic wrist
of FIG. 19;
FIG. 21 is an exploded perspective view of a prosthetic wrist
constructed in accordance with the teachings of an eleventh
embodiment of the present invention;
FIG. 22 is an exploded side elevation view of the prosthetic wrist
of FIG. 21;
FIG. 21A is an exploded perspective view of a prosthetic wrist
constructed in accordance with the teachings of various embodiments
of the present invention;
FIG. 22A is an exploded side elevation view of the prosthetic wrist
of FIG. 21A;
FIG. 23 is an exploded side elevation view of a prosthetic wrist
constructed in accordance with the teachings of a twelfth
embodiment of the present invention;
FIG. 24 is an exploded side elevation view of a prosthetic wrist
constructed in accordance with the teachings of a thirteenth
embodiment of the present invention;
FIG. 25 is a sectional view taken along the line 25-25 of FIG.
24;
FIG. 26 is an exploded side elevation view of a prosthetic wrist
constructed in accordance with the teachings of a fourteenth
embodiment of the present invention; and
FIG. 27 is a sectional view taken along the line 27-27 of FIG.
26.
FIG. 28 is a posterior to anterior view of the carpal complex;
FIG. 29A is a plan view of a carpal implant according to various
embodiments;
FIG. 29B is a plan view of a carpal implant according to various
embodiments;
FIG. 30 is a plan view of a carpal implant according to various
embodiments;
FIG. 31 is an environmental view of the carpal implant according to
various embodiments of FIG. 30 implanted;
FIG. 32 is a distal radial implant according to various
embodiments;
FIG. 33 is a stem portion of a distal radial implant according to
various embodiments;
FIG. 34A is a plan view of a distal radial segment of a modular
distal radial implant according to various embodiments;
FIG. 34B is a perspective view of the distal radial segment of FIG.
34A;
FIG. 35A is a plan view of distal radial segment for a distal
radial implant according to various embodiments;
FIG. 35B is a perspective view of the distal radial segment of FIG.
35A;
FIG. 36A is a plan view of a distal radial segment implant
according to various embodiments;
FIG. 36B is a perspective view of the distal radial implant of FIG.
36A;
FIG. 37 is an environmental view of the distal radial implant of
FIG. 36A in an implanted position;
FIG. 38A is a distal radial segment of the distal radial implant
according to various embodiments;
FIG. 38B is a perspective view of the distal radial segment of FIG.
38A;
FIG. 39A is a plan view of a bearing portion for a distal radial
segment according to various embodiments;
FIG. 39B is a perspective view of the bearing portion of FIG. 39A
according to various embodiments;
FIG. 40A is a plan view of a bearing portion for a distal radial
implant according to various embodiments;
FIG. 40B is a perspective view of the bearing portion of FIG.
40A;
FIG. 41 is a perspective view of a distal radial implant according
to various embodiments;
FIG. 42 is a perspective view of a distal radial implant according
to various embodiments;
FIG. 43 is an environmental view of the distal radial implant of
FIG. 42 according to various embodiments in an implanted position;
and
FIG. 44 is a kit view of various embodiments of the present
invention.
FIG. 45 is an environmental view of a carpal implant in a
hemi-arthroplasty implantation.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS
The following description of various embodiments is merely
exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
With reference to FIGS. 2 and 3 of the drawings, a prosthetic wrist
constructed in accordance with the teachings of the present
invention is generally indicated by reference numeral 50. The
prosthetic wrist 50 is illustrated in a post operative condition as
implanted to a distal portion 2a of the radius 2 and a distal
portion 6a of the carpal bone complex 6. As those skilled in the
art will appreciate, the distal portion 2a of the radius 2 and the
distal portion 6a of the carpal bone complex 6 are formed when the
surgeon resects a portion of the radius 2 and the carpal bone
complex 6 from the patient prior to implantation of the prosthetic
wrist 50.
The prosthetic wrist is illustrated to include a radial implant 52,
a carpal implant 54, a wrist bearing component 56 and a plurality
of bone screws 58. The radial implant 52 includes a radial stem 60,
which is configured to be implanted into a distal portion 2a of the
radius 2, and a bearing guide 62, which is fixed to the distal end
of the radial stem 60. The bearing guide 62 includes a bearing or
concave guide surface 64 that is configured to engage in a mating
manner the wrist bearing component 56. In the preferred embodiment,
the radial implant 52 is unitarily formed from a titanium material,
such as Ti-6Al-4V (F136), although those skilled in the art will
understand that other materials having sufficient strength and
biocompatibility may also be employed. Those skilled in the art
will also understand that the radial implant 52 may be configured
in a modular manner, wherein the radial stem 60 and the bearing
guide 62 are discrete elements that are coupled together prior to
or during the process of implantation. It will also be understood
that the bearing guide 62 may be integrally formed or molded onto
the radial implant 52 and formed of a selected material. For
example, the bearing guide 62 may be formed of a polyethylene
material or other polymer to be formed with the radial stem 60.
Therefore the radial implant 52 may include a proximal radial stem
on a distal radial portion over which the bearing guide portion 62
is formed. Nevertheless, as discussed above, the bearing guide
portion 62 may be formed of any appropriate material such as a
ceramic, or a metal including titanium and cobalt chromium
molybdenum alloy.
With additional reference to FIGS. 3 and 4, the carpal implant 54
is illustrated to include a body 70, a ulnar flange 72 and a radial
flange 74. The carpal implant 54 is unitarily formed from a
titanium material, such as Ti-6Al-4V (F136), although those skilled
in the art will understand that other materials having sufficient
strength and biocompatibility may also be employed.
The body 70 includes a stem 80, a proximal stem 82 and an
interconnecting flange 84. The stem 80, which is formed along a
stem axis 86 and extends from the distal side of the body 70, is
configured to be inserted into a hole formed in the capitate 20
(FIG. 2). The proximal stem 82 extends in a direction opposite the
stem 80 and is sized to engage the wrist bearing component 56. In
the particular embodiment illustrated, the proximal stem 82 is
formed as a tapered cylinder having an axis 88 that is offset
ulnarly from the stem axis 86. Those skilled in the art will
appreciate, however, that the axis 88 of the proximal stem 82 may
be coincident with the stem axis 86. The taper of the proximal stem
82 is configured to the profile of a conventional Morse taper for
attachment to the wrist bearing component 56. A fillet radius R is
employed to reduce the concentration of stress at the points at
which the stem 80 and the proximal stem 82 are joined to the
remainder of the body 70.
The interconnecting flange 84 couples the stem 80 to the ulnar
flange 72. The interconnecting flange 84 includes an
interconnecting bone abutment surface 90 that is skewed to the stem
axis 86 by an angle that is less than 90 degrees in magnitude and
which is preferably about 80 degrees to permit the interconnecting
flange 84 to conform to the proximal end of the distal portion 6a
of the carpal bone complex 6.
The ulnar flange 72 is coupled to a side of the interconnecting
flange 84 proximate the stem 80 and has a lateral bone abutment
surface 96 that is configured to abut an ulnar side of the hamate
22 and which projects upwardly from the body 70 in a manner that is
skewed to both the stem axis 86 and the interconnecting bone
abutment surface 90 by an angle of less than 90 degrees. A securing
aperture 98a, which is formed in the distal end of the ulnar flange
72 along an axis that is generally perpendicular to the lateral
bone abutment surface 96, is illustrated to include a first portion
100 and a second portion 102. The first portion 100 of the securing
aperture 98a has a spherical shape that is configured to matingly
engage the frusto-conical surface of the head 58a of a bone screw
58. (FIG. 3). The second portion 102 of the securing aperture 98a
has a generally cylindrical shape that is sized to receive the body
58b of the bone screw 58.
In the particular embodiment illustrated, the ulnar bone abutment
surface 96 is arranged at an angle of about 50 degrees relative to
the stem axis 86. The distal end of the ulnar flange 72 terminates
at an arcuate edge 104 that is defined by a radius that is centered
at the centerpoint of the securing aperture 98a. As those skilled
in the art will readily appreciate, however, the center of the
radius need not be centered at the centerpoint of the securing
aperture 98a.
The radial flange 74 is coupled to the body 70, and more
specifically to the interconnecting flange 84, on a side opposite
the ulnar flange 72 and includes a medial bone abutment surface 110
that is configured to abut a radial side of the distal portion 6a
of the carpal bone complex 6 and which projects upwardly from the
body 70 in a manner that is skewed to the stem axis 86 by an angle
of less than 90 degrees. In the particular embodiment illustrated,
the radial bone abutment surface 110 is skewed to the stem axis 86
by an angle of about 80 degrees. Like the ulnar flange 72, the
radial flange 74 includes a securing aperture 98b and terminates at
its distal end at an arcuate edge 112 that is defined by a radius
that is centered at the centerpoint of the securing aperture 98b.
The securing aperture 98b is substantially identical to the
securing aperture 98a but is formed about an axis that is generally
perpendicular to the radial bone abutment surface 110.
In view of the above discussion, those skilled in the art will
appreciate that one general concept of the present invention is the
provision of a carpal implant having radial and ulnar flanges that
are configured to abut portions of the carpal bone complex (whether
resected or not) in a way that supports the bones of the radial and
ulnar sides of the carpal bone complex. Accordingly, those skilled
in the art will appreciate that the carpal implant of the present
invention may be formed in any generally concave manner (i.e.,
wherein at least a portion of each of the radial and ulnar flanges
is skewed to the axis of the body) that is configured to abut the
radial and ulnar sides of the carpal bone complex (whether resected
or not). Other examples of the "concave" formation of the carpal
implant of the present invention are illustrated in FIGS. 10
through 12 and 15 through 27 and will be described in detail
below.
With renewed reference to FIGS. 2 and 3 and additional reference to
FIGS. 5 and 6, the wrist bearing component 56 has the general shape
of an ellipsoidal segment and includes a generally flat abutting
edge 120 and a wrist bearing surface 122. As those skilled in the
art will appreciate, the wrist bearing surface 122 does not extend
to a point where it intersects the abutting edge 120 as this would
cause the wrist bearing component 56 to be too large in size.
Accordingly, the flat sides at which the wrist bearing surface 122
terminates permit the wrist bearing surface 122 to be shaped in a
desired manner while maintaining proper sizing of the wrist bearing
component 56. A securing feature 124 is formed into or otherwise
coupled to the abutting edge 120 to permit the wrist bearing
component 56 to be secured to the proximal end of the carpal
implant 54. In the particular example provided, the securing
feature 124 is a blind tapered hole that is configured to matingly
engage the proximal stem 82. Those skilled in the art will readily
understand, however, that any appropriate coupling means may be
employed to couple the wrist bearing component 56 to the carpal
implant 54 and as such, the scope of the present invention will not
be so limited as to require the coupling of the wrist bearing
component 56 and the carpal implant 54 through the engagement of a
tapered stem with a tapered hole. As those skilled in the art will
appreciate, the modular nature of the wrist bearing component 56
permits the surgeon to select from a variety of wrist bearing
components 56 that are differently sized and/or shaped to permit
the surgeon to tailor the prosthetic wrist 50 to the individual
needs of the patient. Those skilled in the art will also appreciate
that the surgeon's selection of a particular wrist bearing
component 56 may necessitate the use of a particular radial implant
52 that has a correspondingly different size and/or
configuration.
The wrist bearing component 56 is preferably formed from a cobalt
chromium alloy, such as CoCrMo, which provides fatigue and
corrosion resistance, as well as a relatively high degree of
strength. Those skilled in the art will understand that other
appropriate materials, including metals and/or plastics, may
alternatively be employed to form the wrist bearing component 56 or
a portion thereof which includes the wrist bearing surface 122.
With particular reference to FIGS. 5 and 6, the wrist bearing
surface 122 is illustrated as being defined by a first radius 130
in the coronal plane and a second radius 132 in the sagittal plane.
Preferably, the first and second radii 130 and 132 are different
and more preferably, the first radius 130 is larger than the second
radius 132. Configuration of the wrist bearing component 56 in this
manner permits the prosthetic wrist 50 to move in a manner that
more closely approximates the motion of a natural wrist.
In situations where the wrist bearing surface 122 is contoured in a
manner that is not defined by a single spherical radius, the
orientation of the wrist bearing component 56 relative to the
radial implant 52 is critical. Accordingly, the prosthetic wrist 50
preferably also includes an alignment mechanism 150 in such
situations for radially fixing the wrist bearing component 56
relative to the carpal implant 54 as is illustrated in FIG. 7.
Preferably, the alignment mechanism 150 permits the surgeon
implanting the prosthetic wrist 50 to orient the wrist bearing
surface 122 to a predetermined installation orientation that is
dependent upon the orientation between the implanted carpal implant
54 and the implanted radial implant 52. For example, if the radial
implant 52 were to be fixed to the distal portion 2a of the radius
2 in a manner that was rotated slightly from that which was
considered "nominal", the surgeon may be able to compensate for the
slight radial offset by rotating the wrist bearing component 56
relative to the carpal implant 54 in an equivalent manner.
The alignment mechanism 150 may permit the wrist bearing component
56 to be rotated in an infinite number of positions relative to the
carpal implant 54, as would the connection of the wrist bearing
component 56 to the carpal implant 54 through the Morse taper
connection of the proximal stem 82 and the blind tapered hole of
the securing feature 124, or through adhesives, or recessed screws
that extend through the wrist bearing component 56 and which engage
the body 70 of the carpal implant 54 (not illustrated).
In the particular example provided, the alignment mechanism 150
permits the wrist bearing component 56 to be rotated into one of a
plurality of predetermined orientations 152. In this regard, the
alignment mechanism 150 is illustrated to include a coupling member
154, which is coupled to the carpal implant 54, and a plurality of
holes 156 that are formed into the wrist bearing component 56. Each
of the holes 156 is sized to receive the coupling member 154 and is
defined by a centerline 158 that is spaced circumferentially apart
from the centerline 158 of an adjacent hole 156. Rotation of the
wrist bearing component 56 relative to the carpal implant 54 is
accomplished via engagement of the coupling member 154 into an
associated one of the holes 156 that permits the wrist bearing
component 56 to be placed in the installation orientation relative
to the radial implant 52. Those skilled in the art will understand
that the coupling member 154 may be removably coupled to the carpal
implant 54 so as to provide the surgeon with an option not to use
the coupling member 154 should the surgeon need more flexibility in
positioning the wrist bearing component 56 relative to the carpal
implant 54. Those skilled in the art will also understand that the
coupling member 154 and the holes 156 may be reversed (i.e., the
coupling member 154 may be attached to the wrist bearing component
56 and the holes 156 may be formed in the carpal implant 54).
In another preferred form, the present invention provides a method
for implanting a prosthetic wrist 50 between the radius 2 and the
portion 6a of the carpal bone complex 6 of a patient. The method
includes: providing a carpal implant 54 including a body 70, a
ulnar flange 72 and a radial flange 74, the body 70 having a stem
80 that is arranged along an axis 86, the ulnar flange 72 being
coupled to the body 70 and extending therefrom, the ulnar flange 72
having a lateral bone abutment surface 96, at least a portion of
the lateral bone abutment surface 96 being skewed to the axis 86 of
the stem 80 by an angle of less than 90 degrees, the radial flange
74 being coupled to the body and extending therefrom on a side
opposite the ulnar flange 72, the radial flange 74 having a medial
bone abutment surface 110, each of the ulnar and radial flanges 72
and 74 having a bone screw aperture 98a, 98b, respectively, formed
therethrough; resectioning the carpal bone complex 6 along lines
that are skewed to an axis of the capitate 20 and which correspond
to the distal faces of the ulnar and radial flanges 72 and 74 and
the interconnecting flange 84; forming an opening in the capitate
20 that lies along an axis that is generally coincident with the
axis of the capitate 20; forming a pair of securing apertures 160
(FIG. 2) into the distal portion 6a of the carpal bone complex 6,
one of the pair of securing apertures 160 being formed in the
hamate 22; securing the carpal implant 54 to the distal portion 6a
of the carpal bone complex 6 such that the stem 80 is at least
partially disposed in the opening in the capitate 20 and engaged to
the capitate 20; providing a first and second screws 58, the first
and second screws 58 being appropriately sized to the pair of
securing apertures 160 and the bone screw apertures 98a, 98b;
placing the first screw through the bone screw aperture 98a in the
ulnar flange 72 and the securing aperture 160 in the hamate 22 and
securing the first screw to the hamate 22 to bring the lateral bone
abutment surface 96 into abutment with an ulnar side of a hamate
22; and placing the second screw 58 through the bone screw aperture
98b in the radial flange 74 and the other securing aperture 160 in
the distal portion 6a of the carpal bone complex 6 and securing the
second screw 58 to the distal portion 6a of the carpal bone complex
6 to bring the medial bone abutment surface 110 into abutment with
a radial side of the distal portion 6a of the carpal bone complex
6.
Preferably, the method also includes: providing a wrist bearing
component 56 having a wrist bearing surface 122 that is defined by
a first radius 130 in the coronal plane and a second, different
radius 132 in the sagittal plane; coupling the wrist bearing
component 56 to a proximal stem 82 formed on the body 70 of the
carpal implant 54 such that the wrist bearing component 56 is
rotatable relative to the carpal implant 54; and fixing the wrist
bearing component 56 to the proximal stem 82 such that the wrist
bearing component 56 is aligned at a predetermined installation
orientation relative to the distal portion 6a of the carpal bone
complex 6.
While the carpal implant 54 has been described thus far as being
unitarily formed and used in conjunction with a discrete wrist
bearing component 56, those skilled in the art will appreciate that
the invention, in its broader aspects, may be constructed somewhat
differently. For example, the carpal implant 54a may be configured
to include a discrete flange structure 200 and a discrete stem 80a
as illustrated in FIG. 8. The flange structure 200 is unitarily
formed from a suitable material, such as CoCrMo, and includes a
bone abutment surface 202. In the particular example provided, the
bone abutment surface 202 is shown to include an interconnecting,
lateral and medial bone abutment surfaces 90a, 96a and 110a,
respectively, which mimic the configurations of the
interconnecting, lateral and medial bone abutment surfaces 90, 96,
110 (FIG. 3), respectively.
The stem 80a is illustrated to include a tapered cylindrical
portion 206, which is configured to be fitted to a hole that is
formed in the capitate 20 (FIG. 2), and a connecting portion 210
for coupling the stem 80a to the flange structure 200. The tapered
cylindrical portion 206 is generally similar to the stem 80 (FIG.
3) discussed above and includes a porous coating 212. The coating
212 or surface may also be plasma sprayed or roughened to form an
uneven or unsmooth surface and need not be porous.
In the example provided, the connecting portion 210 includes a
threaded end portion 220, which is coupled to a proximal end of the
tapered cylindrical portion 206, and a driving portion 224, which
is coupled to an end of the tapered cylindrical portion 206
opposite the threaded end portion 220. The threaded end portion 220
is configured to extend through a stem receiving aperture 230 that
is formed in the flange structure 200 and threadably engage a
threaded aperture 232 that is formed in the wrist bearing component
56a. The driving portion 224 is illustrated to include a geometric
feature, such as a male hexagon shank 240, that permits the stem
80a to be rotated with an appropriately configured tool 242 such
that the threaded end portion 220 threadably engages the threaded
aperture 232 in the wrist bearing component 56a. Those skilled in
the art will readily understand that the driving portion 224 may be
of any shape (e.g., triangular, square, Torx.RTM.) and may extend
from the tapered cylindrical portion 206 in the form of a shank, or
be recessed into the tapered cylindrical portion 206, in which case
the tool 242 would have a corresponding male end to engage the
driving portion 224, rather than a corresponding female as
illustrated in this example.
With the exception of the threaded aperture 232 and a pair of
anti-rotation tabs 246, the wrist bearing component 56a is
otherwise identical to the wrist bearing component 56 of FIG. 2.
The anti-rotation tabs 246 are configured to abut a proximal side
of the flange structure 200 when the wrist bearing component 56a is
coupled to the carpal implant 54a to thereby inhibit relative
rotation between the wrist bearing component 56a and the carpal
implant 54a. Those skilled in the art will appreciate, however,
that other anti-rotation means may additionally or alternatively be
incorporated into wrist bearing component 56a and/or the carpal
implant 54a, including mating geometric features (e.g., a male hex
protrusion formed onto the proximal side of the flange structure
200 and a mating hex recess formed into the distal side of the
wrist bearing component 56a), fasteners and pins. The use of
anti-rotation tabs 246 provides the wrist bearing component 56 with
a relatively greater range of motion as comparatively illustrated
by the angles .alpha. and .beta..
The modular configuration described above provides the surgeon with
a relatively high degree of flexibility when differently sized
components are available in a kit form as shown in FIG. 9. In the
example illustrated, several wrist bearing components (i.e., wrist
bearing components 56a and 56a'), several flanges (i.e., flanges
200 and 200') and several stems (i.e., stems 80a and 80a') are
provided in a kit 250. The wrist bearing components 56a and 56a'
are configured with an identical articular shape, but vary in their
overall height dimension h. Similarly, the flanges 200 and 200' and
stems 80a and 80a' are similarly configured, but vary
proportionally to achieve a desired overall width, w, and/or
length, l, for example.
In the embodiments of FIGS. 10 and 11, the carpal implants 54b and
54c are generally similar to the carpal implant 54 (FIG. 3), except
for the configuration of the interconnecting, ulnar and radial
flanges. In FIG. 10, the ulnar and radial flanges 72b and 74b,
respectively, intersect one another and as such, this embodiment
lacks the interconnecting flange 84 of the carpal implant 54. The
ulnar flange 72b is shown to be configured such that the lateral
bone abutment surface 96b is skewed to the stem axis 86 by an angle
of about 30 degrees, while the radial flange 74b is shown to be
configured such that the medial bone abutment surface 110b is
skewed to the stem axis 86 by an angle of about 45 degrees. In FIG.
11, the interconnecting flange 84c is configured such that the
interconnecting bone abutment surface 90c is arcuately shaped. In
the particular example provided, the interconnecting bone abutment
surface 90c is tangent to the lateral and medial bone abutment
surfaces 96c and 110c, respectively.
A further embodiment is illustrated in FIG. 12, wherein the carpal
implant portion 54d and the wrist bearing portion 56d are unitarily
formed from a suitable material, such as CoCrMo. In the particular
embodiment illustrated, the carpal implant portion 54d is
illustrated to include ulnar and radial flanges 72d and 74d,
respectively, that intersect one another in a manner that is
similar to the ulnar and radial flanges 72b and 74b, respectively,
of the carpal implant 54b of FIG. 10. Those skilled in the art will
appreciate, however, that the ulnar and radial flanges 72d and 74d
may be formed differently so as to intersect at any desired angle,
or such that they are spaced apart by an interconnecting portion in
a manner that is similar, for example, to the configurations of the
carpal implants 54 and 54c of FIGS. 3 and 11, respectively.
A sixth embodiment is illustrated in FIGS. 13 and 14, and
illustrates an alternately constructed radial implant 52e, wherein
the bearing guide 62e is formed with an arcuate shape that is
configured to matingly engage the curvilinear cut 300 of a resected
radius 2a'. Those skilled in the art will appreciate that the
curvilinear cut 300 will support the bearing guide 62e and thereby
permit the radial implant 52e to be formed with a relatively lower
profile as compared to the radial implant 52.
A seventh embodiment is illustrated in FIG. 15, wherein the
prosthetic wrist 50f is illustrated to be generally similar to the
prosthetic wrist illustrated in FIG. 8, except for the shape of the
flange structure 200f and the wrist bearing component 56f. More
specifically, the flange structure 200f includes a generally
V-shaped interconnecting flange 84f to which the ulnar and radial
flanges 72f and 74f, respectively, are oppositely coupled. As will
be apparent to those skilled in the art, the wrist bearing
component 56f is contoured to matingly engage the proximal side of
the flange structure 200f and accordingly includes a generally
V-shaped profile 400. In a manner that is similar to the prosthetic
wrist of FIG. 8, the stem 80f includes a threaded end portion 220
that is threadably received into a threaded aperture 232 that is
formed in the wrist bearing component 56f.
An eighth embodiment is illustrated in FIG. 16, which is similar to
the prosthetic wrist of FIG. 8 except for the flange structure
200g. The flange structure 200g of the prosthetic wrist 50g
includes an interconnecting flange 84g with an interconnecting bone
abutment surface 90g with a plurality of portions 500 that are each
defined by a skew angle. The skew angles that define each portion
500 need not be symmetrical about the stem axis 86g. The skew angle
of each portion 500 is less than 90 degrees in magnitude to permit
the interconnecting flange 84g to conform and abut the proximal end
of the distal portion 6a (FIG. 2) of the carpal bone complex 6
(FIG. 2).
A ninth embodiment is illustrated in FIGS. 17 and 18. The flange
structure 200h is generally identical to the flange structure 200g
and as such, will not be discussed in further detail. The wrist
bearing component 56h is generally similar to the wrist bearing
component 56a (FIG. 8) in that the ulnar (lateral) and radial
(medial) portions of the distal side of the wrist bearing component
56h are angled to match the angled proximal surfaces of the ulnar
and radial flanges 72h and 74h, respectively. However, the wrist
bearing component 56h also includes anterior and posterior located
portions 600 on the distal sides of the wrist bearing component 56h
that extend distally in a manner that overlaps the flange structure
200h. The configuration of the wrist bearing component 56h
therefore inhibits both relative rotation and relative
anterior-posterior movement between the wrist bearing component 56h
and the flange structure 200h.
A tenth embodiment, which is also similar to the prosthetic wrist
50g, is illustrated in FIGS. 19 and 20. In this embodiment, the
flange structure 200i is similar to the flange structure 200g
except that the proximal side of the flange structure 200i is
parallel to the distal side of the flange structure 200i (i.e., the
proximal side of the flange structure 200i includes a plurality of
segments that are parallel to the segments that make up the distal
side of the flange structure 200i). As will be apparent to those
skilled in the art, the wrist bearing component 56i is contoured to
matingly engage the proximal side of the flange structure 200i and
accordingly includes a profile 700 that matches the four angled
surfaces that make up the proximal side of the flange structure
200i.
An eleventh embodiment is illustrated in FIGS. 21 and 22, wherein
the prosthetic wrist 50j is illustrated to include a flange
structure 200j and a wrist bearing component 56j. The flange
structure 200j is generally identical to the flange structure 200i
and as such, will not be discussed in further detail. The wrist
bearing component 56j is similar to the wrist bearing component 56i
in that it includes a profile 700j that matches the four angled
surfaces that make up the proximal side of the flange structure
200j. The wrist bearing component 56j also includes anterior and
posterior located portions 600j on the distal sides of the wrist
bearing component 56j that extend distally in a manner that
overlaps the flange structure 200j. Moreover, the flange 200j, may
be any appropriate geometry to substantially compliment or match
the carpal plate.
According to various embodiments, illustrated in FIGS. 21A and 22A,
wherein the prosthetic wrist 50ja is illustrated to include a
flange structure 200ja and a wrist bearing component 56ja. The
flange structure 200ja is generally similar to the flange structure
200i and as such, will not be discussed in further detail.
Nevertheless, it will be understood that the prosthetic wrist 50ja
may include other features and variations. In addition, the flange
200ja may include a proximal surface 201ja that is a substantially
smooth arc or radius, as discussed here.
The wrist bearing component 56ja is similar to the wrist bearing
component 56i in that it includes a profile 700ja that
substantially matches or compliments the proximal side 201ja of the
flange structure 200ja. The proximal side 201ja of the flange
structure 200ja includes a substantially smooth radius or arc. That
is the proximal side 201ja may be defined as an arc rather than a
plurality of angles. The profile 700ja may include a substantially
smooth radius or arc that compliments or matches the arc of the
flange 200ja. Therefore, the flange 200ja and the bearing component
56ja may substantially mate when assembled.
The wrist bearing component 56ja also includes anterior and
posterior located portions 600ja on the distal sides of the wrist
bearing component 56ja that extend distally in a manner that
overlaps the flange structure 200ja. Moreover, the flange 200ja,
including the proximal side 201ja, may be any appropriate geometry
to substantially compliment or match the surface 700ja of the
bearing 56ja.
A twelfth embodiment is illustrated in FIG. 23 and includes a
flange structure 200k and a wrist bearing component 56k. The flange
structure 200k includes a distal surface that is configured
generally identically to the distal surface of the flange structure
200g. The proximal surface of the flange structure 200k, however,
is segregated into a plurality of zones 800a, 800b and 800c. Zones
800a and 800c are generally parallel the ulnar and medial bone
abutment surfaces 96k and 110k. Zone 800b, which is coupled at its
opposite ends to zones 800a and 800c, is defined by a radius that
tangentially intersects zones 800a and 800c. The wrist bearing
component 56k includes a profile 700k that matches the proximal
surface of the flange structure 200k.
In FIGS. 24 and 25, a thirteenth embodiment is illustrated to
include a flange structure 200m and a wrist bearing component 56m.
The distal side of the flange structure 200m is configured in a
manner that is generally identical to the distal side of the flange
structure 200k discussed above. The proximal side 900 of the flange
structure 200m, however, is defined by a spherical radius 902. In
the particular embodiment illustrated, the spherical radius 902 is
centered at a point that is disposed along the axis 904 of the
connecting portion 210m. Those skilled in the art will appreciate,
however, that the center of the spherical radius 902 may be
positioned otherwise. The wrist bearing component 56m likewise
includes a distal profile 700m that matingly engages the proximal
side 900 of the flange structure 200m.
In FIGS. 26 and 27, a fourteenth embodiment is illustrated to
include a flange structure 200n and a wrist bearing component 56n.
The flange structure 200n is generally similar to the flange
structure 200m, except that the proximal side 900n is defined by a
first radius 1002 in the coronal plane and a second radius 1004 in
the sagittal plane. The wrist bearing component 56n is likewise
generally similar to the wrist bearing component 56m, except that
the distal profile 700n of the wrist bearing component is
configured with a first radius in the coronal plane and a second
radius in the sagittal plane so as to matingly engage the proximal
side 900n of the flange structure 200n.
While some embodiments have been illustrated to include a unitarily
formed component, such as a unitarily formed carpal implant, and
others have been illustrated to include a component assembly, such
as a carpal implant assembly that includes a discretely formed stem
and a discretely formed flange structure, those skilled in the art
will appreciate that any unitarily formed component may be formed
in the alternative utilizing a plurality of discretely formed
components and that any embodiment that is shown to be formed using
a plurality of discretely formed components may likewise be
unitarily formed in the alternative.
With reference to FIG. 28, the carpal bone complex 6 includes a
geometry that also angles or curves about a radius between a volar
side 1000 and a dorsal side 1002. The angle is between the volar
side 1000 and the dorsal side 1002 of the carpal complex 6.
Generally the bones including the hamate 22, the triquetrum 12, the
lunate 10, the scaphoid 8, and the trapezium 16 define the dorsal
volar curvature or profile of the carpal complex 6. It may be
selected to include the radius defined by the carpal complex 6 in a
carpal implant. The carpal implant that includes the dorsal volar
radius may allow for a substantially easier implantation of the
carpal implant and allow for a more natural orientation of the
bones of the carpal complex 6 after implantation of the carpal
implant. It will be understood that although specific embodiments
are illustrated for a carpal implant including the selected radius,
that any carpal implant may include the selected radius to allow
for a substantially natural implantation of the carpal implant
relative to the carpal complex 6.
With reference to FIG. 29, a carpal implant 1010 may be provided
that includes a first segment 1012, a second segment 1014, and a
third segment 1016. Between the first segment 1012 and the second
segment 1014 may be a first angle 1018. Between the second segment
1014 and the third segment 1016 may be a second angle 1020. The
first angle 1018 and the second angle 1020 provide a radius about
the volar side 1022 of the carpal implant 1010 that includes a
radius away from the dorsal side 1024 of the carpal implant 1010.
It will be understood that the geometry of the carpal implant 1010
may be included in any appropriate carpal implant, such as various
embodiments discussed above and herein. Nevertheless, it will be
understood that the geometry of the carpal implant 1010 is not
limited to a particular embodiment but may be provided in the
various embodiments.
The carpal implant 1010 may include various bores such as a first
screw bore 1026 and a second screw bore 1028. In addition, a third
bore 1030 may be provided for positioning the stem 80 (FIG. 3) that
is to pass through the carpal implant 1010. Regardless, it will be
understood that the carpal implant 1010 may be provided with a
plurality of portions or included with any of the implants as
described above, or herein, so that the first angle 1018 and the
second angle 1020 are operable to provide the substantially natural
volar radius or dorsal bow for a prosthetic.
With regard to FIG. 29, a carpal implant 1040 may include a member
1042 that extends between a first end 1044 and a second end 1046.
The member 1042 may define a radius 1048. The radius 1048 may
provide that the member 1042 includes a substantially constant
radius or arch between the first end 1044 and the second end 1046.
The arch or angle between the first end 1044 and the second end
1046 may be substantially similar to the arch or angle defined by
the carpal implant 1010 except that the angle or arch of the carpal
implant 1040 is substantially continuous.
The carpal implant 1040 may also include a plurality of portions.
For example, the carpal implant may include a first screw bore 1050
and a second screw bore 1052. In addition, the carpal implant 1040
may include a post bore 1054 that is operable to receive a post, as
described above.
Although the carpal implant 1010 may include a plurality of angles
1018, 1020, and the carpal implant 1040 may include a substantially
continuous radius 1048, each may provide an angle or a bow that is
substantially similar to the carpal complex 6. Therefore, the
carpal implant 1010, 1040 may be implanted into an anatomy in a
substantially natural manner. It will be understood, in addition,
that the portions defining the selected bow or radius may be
included in any appropriate carpal implant. For example, the carpal
implant 54 may include the selected portions and angles that are
substantially angled distally to allow for a formation about the
carpal complex 6. The carpal implant 54 may also include the dorsal
bow that may be defined by the angles 1018, 1020 or the radius
1048. Therefore, it will be understood that the carpal implant may
include a plurality of features to allow it to be implanted into a
selected anatomy.
In addition, it will be understood that the carpal implant may be
substantially interoperatively bowed to achieve a selected angle or
radius. Therefore, during a procedure, a user, such as a surgeon,
may determine that a selected bow or radius is required and forms
the implant to the selected radius. This may be done by cold
working, hot working, bending or any appropriate manner to form the
selected bow or angles. Alternatively, or in addition, the carpal
implant may be substantially customized for a selected individual.
Therefore, pre- or intraoperative measures may be taken of the
patient's anatomy, including the dorsal or volar bow of the carpal
complex 6 to allow for a formation of the selected carpal implant
to substantially mimic that of the natural anatomy of the patient.
This may allow for a more natural implantation of the carpal
implant into the anatomy of the patient for a substantially more
precise anatomical implantation.
With reference to FIG. 30, a carpal implant 1100 is provided. The
carpal implant 1100 may include a carpal complex engaging side 1102
and a proximal side 1104. The carpal implant 1100 may include the
carpal side 1102 that is generally similar to the above-described
carpal implants. For example, the carpal engaging side 1102 may
include a first or ulnar section 1106, a second section 1108, a
third section 1110 (wherein the second section 1108 and the third
section 1110 may define a body), and a fourth, ulnar, or augmented
section 1112. The augmented section 1112 may differ from those
described above and may be provided to replace a selected bone
portion, such as the scaphoid 8 in the carpal complex 6. The
augmented section 1112 may include an augmented or exterior surface
1114 that may substantially replace the articulating surface of the
scaphoid 8 during a procedure. Moreover, the augmented portion 1112
may be substantially integral or modular. Therefore, the carpal
implant 1100 may include a member operable to receive a selected
augmented region 1112 for selection by a user.
The carpal implant 1100 may further include a screw fixation bore
1116 and a post bore 1118. The screw which may be used to pass
through the screw bore 1116 and the post 80 (FIG. 3) may be similar
to those described above. In addition a screw fixation bore 1117
may be formed in the augmented section 1112. This may allow a
fixation screw, such as those discussed above, to be passed through
the augmented section 1112 to engage a portion of the carpal
complex 6. This may allow fixing of the carpal implant 1100 to the
carpel complex 6 in an appropriate manner. In this way it may also
be understood that the surface 1114 does not particularly
articulate with a portion of the carpel complex 6 yet the augmented
section 1112 is operable to fill a void in the carpal complex 6,
such as due to the removal of a selected bone from the carpal
complex 6. Nevertheless, the augmented section 1112 may be provided
to replace a selected boney portion and the remaining boney
portions of the carpal complex 6 may articulate therewith, as
discussed herein. Although it will be understood that the carpal
implant 1110 may be connected to the carpal complex 6 in any
appropriate manner, as mentioned above such that that surface 1114
does not articulate with the carpal complex 6.
The proximal surface 1104 of the carpal implant 1100 may include a
substantially continuous convex radius such that it may articulate
with a radial implant or a portion of the radius. Alternatively,
the carpal implant 1100 may be fixed to a bearing member, such as
the bearing member 56, to articulate with the radial implant. The
carpal implant 1110 may allow for articulation of various portions
of the carpal complex 6 with the other portions of the complex 6
and the radius 2 to allow for substantial replacement of the
natural articulation of the wrist.
With reference to FIG. 31, the carpal implant 1100 may be
positioned in the carpal complex 6 such that the augmented region
1112 replaces the scaphoid bone 8. Therefore, the augmented region
1112 may be able to articulate with the trapezium bone 16 and the
trapezoid bone 18. The augment region may also articulate with the
capitate bone 20 as will be understood by one skilled in the art.
Therefore, a screw, such as the screw 58, may be used to engage the
hamate bone 22 and the carpal implant 1110 is allowed to articulate
freely with the other boney portions of the complex 6.
Nevertheless, the augmented region 1112 need not articulate with
the carpel complex 6.
The resection of the carpal complex 6 may be similar to a resection
otherwise required to implant a carpal implant except that the
scaphoid 8 may be replaced with the augmented region 1112. The
articulating surface 1114 may be defined in such a way that the
augmented region 1112 is operable to articulate with the selected
bony portions to substantially mimic the natural articulation in
the wrist. This may be selected if the scaphoid bone 8 is
substantially removed due to a resection procedure, an injury, or
the like. Therefore, it is not necessary to fix the carpal implant
1110 to a bone portion through the augmented region 1112, but the
other bone portions of the carpal complex 6 may simply articulate
with the augment region 1112.
It will be understood that the carpal implant 1110 may include any
appropriate augments to engage any selected portions of the carpal
complex 6. Therefore, the augmented region 1112 may be provided to
replace the scaphoid bone 8 or other articulating the selected
portions of the scaphoid complex 6. Thus, any appropriate augmented
region of the carpal implant 1110 may be provided.
In addition, other various embodiments may include various portions
that provide for replacement of selected bone segments such as the
augmented region 1112. Thus, the carpal implant 1110, according to
various embodiments or in conjunction with various embodiments, may
be provided to replace a selected or bony portion to allow for a
substantially natural articulation within the carpal complex
regardless of the condition of the carpal complex. The augmented
region 1112 may also be provided to replace other boney portions,
such as the lunate 10. Moreover, the carpal implant 1110, as
mentioned above, may be substantially modular such that the
augmented region 1112 may or may not be included. Moreover, the
augmented region may be selected to replace a selected bone by
selecting a particular module.
In addition, the post 86 may be provided in the carpal implant 1100
to engage the bone portion capitate bone 20 and also engage the
selected bearing member 56. Nevertheless, as discussed above, the
radius side 1104 of the carpal implant 1100 may substantially
provide an articulating or bearing surface to articulate or bear
with the radius 2 or the radial implant 52, or any appropriate
radial implant. Nevertheless, the carpal implant 1110 may
articulate both with the radial portion, such as the radius 2, the
radial implant 52, or any appropriate radial implant, and may also
articulate with selected portions of the carpal complex 6.
Therefore, the carpal implant 1100 may include both the radial side
articulating surface 1104 and the articulating surface 1114
substantially defined by the augmented region 1112. Regardless, the
carpal implant 1100 may be provided to allow for replacement of
selected bony portions, such as those bony portions that are
substantially incapable of providing anatomical support or
articulation, by use of the augmented region 1112. Again, such as
discussed above, the region 1112 need not articulate with the
carpal complex 6 but may fill a mass in the carpal complex 6.
With reference to FIG. 32, a distal radial implant 1200 is
illustrated according to various embodiments. The distal radial
implant 1200 may be provided as a substantially modular implant
that includes a stem portion 1202 that is operable to be positioned
relative to a selected portion of the radius 2, such as
intramedullary. Affixed or interconnected with a selected portion
of the stem portion 1202 is a distal radial segment 1204. The
distal radial segment 1204 may be provided to engage the stem 1202
to provide a selected orientation, configuration, size and other
considerations for the distal radial implant 1200. Furthermore, a
distal radial bearing 1206 may be provided that may engage a
selected portion of the distal radial segment 1204. As discussed
herein, the bearing 1206 may be fixed to the distal radial segment
1204, may articulate with the distal radial segment 1204, or may be
provided in any appropriate configuration. In addition, the bearing
1206 may be omitted, as a bearing extending from the carpal implant
may articulate with the distal radial segment 1204. Alternatively,
the bearing member 1206 may be omitted, as a carpal implant or
portions of the carpal complex 6 may articulate directly with the
distal radial portion 1204. Nevertheless, the modular distal radial
implant 1202 may be provided in a manner allowing a user, such as a
physician, to select a distal radial implant interoperatively to
substantially match the anatomy of a patient.
With reference to FIG. 33, the stem 1202 includes a body portion
1208 and a neck or engaging portion 1210. The neck portion 1210 may
include a connection area, such as a male connection post, to
engage a respective female connecting area, discussed herein, in
the distal radial segment 1204. For example, the stem connection
1210 may include a groove or detent 1212 that is operable to engage
a deflectable member or portion of the distal radial segment 1204.
Nevertheless, the connection member 1210 may be provided to allow
for an interconnection of the stem 1202 with the distal radial
component 1204.
The body portion 1208 of the stem 1202 may include a selected
geometry. For example, the body portion 1208 may be substantially
cylindrical or tapered/conical to allow for easy insertion of the
stem 1202 into the radius 2. The body 1208, however, may include a
selected geometry to substantially resist rotation of the distal
radial implant 1200 after implantation. For example, various
extensions or keys, such as fins or tabs 1214, may be provided that
extend from an exterior of the body 1208 such that the fins 1214
may engage a selected portion of the bone. In addition, the body
1208 may include a selected irregular geometry or regular geometry
that includes portions that may resist rotation. For example, the
body 1208 may include a substantially square or rectangular
cross-section, may define a substantially "I-beam" cross-section,
an oval cross-section, a star cross-section, a cruciform
cross-section, or any appropriate cross-section. Nevertheless, the
body portion 1208 may be provided for allowing both substantially
easy implantation of the modular distal radial implant 1200 and a
mechanism to resist rotation of the distal radial implant 1200
after implantation thereof.
Furthermore, the stem 1202 may be provided in a plurality of
dimensions, such as a diameter, length, curve radius,
cross-section, and combinations thereof. For example, the stem
portion 1202 may include a diameter or a cross-sectional size 1216,
a length 1218, or any other selected dimensions that may be varied.
Therefore, a kit 1600 (FIG. 44), or other appropriate selection may
be provided such that one or more of the stems 1202 may be provided
with one or more variations in the selected dimensions 1216, 1218.
For example, in the kit 1600, a plurality of the stems 1202 may be
provided or each of the stems 1202 include a slightly different
length 1218 such as about 4 cm, about 6 cm, and about 8 cm.
Therefore, during a procedure, such as an implantation of the
distal radial implant 1200, a user, such as a physician, may select
the appropriate length for the stem 1202.
With reference to FIGS. 34A and 34B, the distal radial segment
1204, according to various embodiments, is illustrated as the
distal radial segment 1204a. The distal radial segment 1204a may
include portions that are operable to engage the stem 1202.
Nevertheless, the distal radial portion 1204a may be formed
according to various embodiments, including various embodiments
exemplary illustrated herein, or combinations thereof.
The distal radial component 1204a generally includes a body portion
1230 and a superior or articulating portion 1232. The body portion
may be formed in any appropriate manner to engage a selected
portion of the anatomy. The body 1230 may include selected
dimensions such as a length 1234, a width 1236, a height 1238, and
an arch or radius 1240. The various dimensions 1234, 1236, 1238,
and 1240 may be varied for various applications. As discussed
above, and in conjunction with the stem 1202, a plurality of the
distal radial segments 1204a each including a unique set of
dimensions 1234-1240 may be provided. Each may be provided in a
large inventory or in the kit 1600 (FIG. 44) for selection by a
user substantially intraoperatively or preoperatively.
Nevertheless, various sizes or configurations of the distal radial
implants 1204a may be provided to allow for a substantially
customized fit with a selected patient.
The distal radial component may also include the articulating
region or portion 1232 that may also include a plurality of
selected dimensions. For example, the articulating region 1232 may
include a length 1242 and a width 1244. The articulating region
1232 may also include an articulation depth 1246 that may vary
depending upon a selected application. The articulation depth 1246
may generally be understood to be the deepest portion of the
concave region 1248 that defines the articulating surface of the
articulating region 1232. The uppermost portion of the height 1246
may be a point where the articulating surface stops or transforms
into a lip 1252. Therefore, the upper portion 1250 of the
articulating surface may extend to the edge of the articulating
region 1232 or may stop intermediate thereof. Again the
articulating region 1232 including the various dimensions 1242-1246
may be varied and unique for a plurality of the implants 1204a.
Therefore, again, the user may select the distal radial implant
1204a according to selected requirements or dimensions of a
patient.
The distal radial implant 1204a may define a selected geometry of
the body 1230. For example, the body may include a single or
plurality of depressions 1254 for various reasons. For example, the
depressions 1254 may assist in allowing for a fixation of the
distal radial implant 1204a to a selected portion of the anatomy.
In addition, the body 1230 may be substantially smooth over the
surface thereof or include other various selected geometries. Again
a plurality of geometries may be selected for various uses during
an implantation.
The articulating region 1232 may include the first lip 1252 and a
second lip 1256. The lips 1252, 1256 may extend a distance beyond
an edge of the body 1230. The lips 1252, 1256 may be dimensioned
depending upon a selected portion of the anatomy or a selected
patient.
Defined in the body 1230 is a female receiving or interconnection
portion or depression 1260. The female interconnection 1260 may
include a dimension that allows for substantial interconnection
with the male interconnection 1210 of the stem 1202. The reception
or interconnection portion 1260 may include a deformable member
(such as a canted coil spring or screw or other mechanism) 1262, or
screw which may engage the depression 1212 of the stem 1202.
Therefore, the distal radial component 1204a may be interconnected
with the stem 1202 for an implantation. It will be understood, that
the body 1230 may define a male connection and the stem define a
female connection. Thus the interconnection may be performed in any
appropriate manner and these are merely exemplary.
With reference to FIGS. 35A and 35B, a distal radial implant 1204
according to various embodiments of a distal radial implant 1204b
is illustrated. The distal radial implant 1204b includes portions
similar to the distal radial implant 1204a and like numerals will
be used to indicate like portions. The distal radial implant 1204b
includes a body portion 1270 and an articulation portion 1272. The
body 1270 may be substantially similar to the body 1230 of the
distal radial implant 1204a. Nevertheless, the articulation region
1272 may include a projection or flat spot 1274. The flat spot 1274
may be viewed as a portion of the body 1270 but extends a distance
substantially parallel to a base 1276 of the body 1270. The flat
portion 1274 may substantially abut a distal portion of the radius
2 during and after implantation. Therefore, the flat portion 1274
may allow for a substantially stable interconnection with the
radius 2 after the implantation. Alternatively, the flat portion
1274 may be provided for a further connection or fixation portion
to engage the radius 2.
Nevertheless, the distal radial implant 1204b may include the
plurality of dimensions 1234, 1236, 1238, 1240, 1242, 1244, and
1246. As discussed above, the plurality of dimensions may be
substantially unique and different among a plurality of the distal
radial implants 1204b for a modular interconnection and selection
by a user. In addition, the flat portion 1274 may be provided on
the distal radial implant 1204b as one of a plurality of the distal
radial implants 1204 that may be provided in an inventory or the
kit 1600 for use by a user. Therefore, the distal radial implant
1204b may be provided for forming a distal radial implant 1200
depending upon a selected patient.
With reference to FIGS. 36A and 36B, a distal radial implant 1204
according to various embodiments of a distal radial implant 1204c
is illustrated. The distal radial implant 1204c may include
portions that are similar to the portions of the distal radial
implant 1204a and like numerals are used to reference like portions
of the distal radial implant 1204c. In addition, it will be
understood that the distal radial implant 1204c may include
portions that are selectable to be used with other various
embodiments of the distal radial implant 1204a and the distal
radial implant 1204c is merely exemplary.
The distal radial segment 1204c includes a body 1280 that may be
similar to the body 1230 of the distal radial implant 1204a.
Therefore, the body 1280 may also include the female engaging
portion 1260 operable to engage a selected portion of the stem
1202. Nevertheless, as discussed above, the female engaging portion
1260 may be any appropriate size, configuration and the like. In
addition, any appropriate portion may be provided to engage the
stem 1202. In addition, the body 1280 may include selected
portions, such as depressions, dimensions and the like that may be
substantially different for a selected use or patient.
Extending distally from the body 1280 is the carpal engaging region
or portion 1282. The carpal engaging region 1282 is formed to
extend from the body 1280 to engage a selected portion of the
carpal complex 6. The bones of the carpal complex 6 may be held
within the carpel engaging portion 1282 so that the bones of the
carpal complex 6 are operable to articulate in a generally natural
manner but may be held relative to one another to allow for a
fixation of the wrist relative to the distal portion of the radius.
Essentially the holding portion 1282 may surround a selected number
or volume of the carpal complex 6 to allow for retention of the
natural boney portion after implantation of the distal radial
segment 1204c.
The distal radial segment 1204c may be provided for a substantially
hemi-arthroplasty where substantially only the distal portion of
the radius 2 is replaced. The distal radial segment 1204c may
articulate with the carpal complex 6 to reduce the need for a
carpal implant.
With reference to FIG. 37, the distal radial implant segment 1204c
may be implanted to substantially capture or surround selected
portions of the carpal complex 6 such as the scaphoid 8, the lunate
10, the triquetrum 12, and the trapezium 14. Therefore, if any
portions of these bones are resected or if the portions of the
carpal complex 6 are left substantially whole, they may be enclosed
within the carpal complex portion 1282 of the distal radial implant
1204c It will be understood that the containing portion 1282 may be
shaped and sized for any appropriate application and may include a
selected geometry for holding or fixing a selected number of the
bones of the carpal complex 6. Moreover, a bearing component may be
fit or molded onto the container portion 1282 to allow for a
substantially smooth articulation of the various bones of the
carpal complex 6 relative to the distal radial implant segment
1204c
Returning reference to FIGS. 36A and 36B, the distal radial implant
segment 1204c includes the carpal engaging section 1282 which may
include a plurality of selected dimensions. For example, the carpal
containing section 1282 may include a selected high or ulnar side
1284 and a radial side 1286. This may allow for the carpal engaging
section 1282 to substantially mimic the natural shape of the distal
radial portion and how it would engage the carpal complex 6. For
example, the distal radial implant 1204c may engage and hold the
carpal complex bone 6 in a selected orientation and shape.
Therefore, the high side 1284 may include high side height 1288 and
a low side 1286 may include a low side height 1290. Furthermore,
the carpal containing section 1282 may include a length 1292 and a
width 1294. Therefore, the carpal containing section 1282 may
include a plurality of dimensions 1288-1294 that may be selected
and varied depending upon a particular patient or user. In
addition, as discussed above, a plurality of the radial distal
implants 1204c may be provided in either an inventory or kit 1600
for selection during a procedure to allow for a substantial
customization of the implant for a selected patient.
Nevertheless, the carpal containing selection 1282 may allow for
holding a selected number of the carpal bones in the carpal complex
6 in a selected manner for a substantially natural articulation.
The carpal containing section 1282 may hold portions of the carpal
complex 6 in a manner such as to allow for an articulation of even
a weakened or fractured carpal complex. In addition, the carpal
containing section 1282 may be used when various portions of the
anatomy may be resected, such as removal of the entire proximal row
of the carpal complex 6. In addition, the carpal containing section
1282 may retain resected portions of the bone segments that form
the proximal row of the carpal complex 6 and may allow for
collecting the portions of the carpal complex in such a manner to
allow for articulation of the carpal complex 6 relative to the
radius 2 by way of the distal radius segment 1204c.
With reference to FIGS. 38A and 38B, a distal radial implant 1204
according to a various embodiment of a distal radial implant 1204d
is illustrated. The distal radial implant 1204d may include
portions similar to the distal radial implant 1204a and like
numerals are used to indicate like portions.
The distal radial implant 1204d may be similar to the distal radial
implant 1204c in that both may be used for a substantially
hemi-arthroplasty of the wrist including a resurfacing or
arthroplasty of substantially only the radius bone 2 or the distal
radial portion. Therefore, the distal radial segment 1204d may
include a body 1290 that includes the female engaging portion 1260.
The distal radial implant segment 1204d may interconnect with the
stem 1202 to allow for formation of a selected distal radial
implant. In addition, the body portion 1290 may include selected
detents and other formations to allow for an implantation of the
distal radial implant 1204d+into a selected anatomy.
Extending from the body portion 1290 is an articulating or carpal
portion 1292. The carpal portion 1292 may include a ulnar or first
side 1294 and a radial or second side 1296. Extending between the
two sides 1294, 1296 is a surface, such as an articulation surface
1298. The articulation surface 1298 may be a substantially metal
articulation surface that does not necessarily require a bearing,
such as a polymer bearing. The articulating surface 1298 may be
used to articulate with a selected portion of the carpal complex in
a substantially hemi arthroplasty replacement. Therefore, the
articulating surface 1298 may be substantially a metal, or any
other appropriate material, including a plastic, ceramic,
pyrocarbon (also referred to as pyrolytic carbon), portion such
that the body 1290 and the articulating region 1292 may be formed
as a substantially single portion.
The articulating region 1298 may be provided in such a manner to
articulate with a selected portion of the carpal complex 6 in a way
that allows for replacement of only the distal portion of the
radius 2 without augmentation of the carpal complex 6. Therefore,
particularly in selected situations such as a fracture, chip and
the like of the radius 2, the distal radial implant 1204d may be
used to resurface the selected portion of the radius 2 without
requiring a carpal implant.
The articulating region 1292 may include selected dimensions such
as a height 1300, a length 1302, and a width 1304 that may be
different or selected depending upon a use or patient. For example,
a selected size of the carpal complex 6 may require a selected size
of the articulating region 1298 to engage the carpal complex 6 in a
selected manner. In this way, the articulating portion 1298 may
articulate with the carpal complex 6 to allow for replacement of
substantially only the distal portion of the radius 2 rather than a
replacement of a portion of the carpal complex 6 and a carpal
implant.
Although the articulating region 1298 may be a substantially metal
or hard material, such as a ceramic or pyrocarbon, articulating
region, it will be understood that the articulating region 1298 may
also include a bearing. The bearing may include a polymer bearing,
such as a bearing formed of a ultra-high molecular weight
polyethylene or any other appropriate bearing portion.
Alternatively, the bearing surface 1298 may simply be a highly
polished surface which allows for substantially easy, smooth
articulation of portions of the carpal complex 6 relative to the
distal radial implant segment 1204d. It will be understood,
therefore, that the various distal radial implants 1204 may be used
for a complete or hemi arthroplasty of the radius 2.
With reference to FIGS. 39A and 39B, a bearing component 1206
according to selected embodiments of a bearing component 1206a is
illustrated. The bearing 1206a may be interconnected with a
selected distal radial implant 1204 according to various
embodiments. Therefore, it will be understood that the bearing
portion 1206a may be affixed to a selected one of the distal radial
implants such as the distal radial implant 1204a.
The bearing components 1206a includes an articulation or carpal
bearing side 1310 that defines a bearing surface 1312. The bearing
component 1206a also defines a distal radial bearing side 1314. The
distal radial bearing side 1314 defines a distal radial bearing
surface 1316. The distal radial bearing surface 1316 is provided to
substantially seat within the bearing side 1232 of the distal
radial implant 1204.
The bearing 1206a may be substantially fixed to the distal radial
component 1204a in any appropriate manner. For example, the bearing
1206a may be adhesively affixed, mechanical affixed, welded,
otherwise bonded, or the like. For example, a selected deformable
or engagable lip or edge 1318 may be provided to engage the lip
1252 and, 1256 of the distal radial implant 1204a. Alternatively,
various locking portions such as screws, bars, and the like may
substantially interconnect the bearing components 1206a with the
distal radial components 1204a. Therefore, the bearing components
1206a may substantially be held relative to the distal radial
component 1204a allowing for a substantially stable base of
articulation of the carpal complex 6 and portions of the wrist
relative to the varying portion 1206a and the distal radial implant
1204a.
The articulating surface 1312 of the distal radial implant 1206a
may allow for articulation of selected portions of the distal
carpal complex 6. The carpal complex 6 may be allowed to articulate
within the articulating surface 1312 to allow for a natural
articulation of the wrist relative to the implant 1200.
Alternatively, the articulating surface 1312 may be provided to
articulate with a selected portion of the carpal implant according
to various embodiments. For example, the carpal bearing member 56
may be provided to articulate within the articulating surface 1312
of the bearing member 1206a. Therefore, a total wrist replacement
may be provided that includes the carpal implant 54 and the carpal
bearing implant 56. The carpal bearing implant 56 may include a
substantially polymer or a substantially metallic surface.
Nevertheless, it is generally selected to provide a metal on
polymer bearing articulation such that the bearing member 1206a may
be formed of either a polymer or a metal portion.
Alternatively, a carpal implant such as the carpal implant 1100 may
be provided. The articulating surface 1104 of the carpal implant
1100 may be allowed to articulate with the articulating surface
1312 of the bearing member 1206a. Therefore, the carpal implant
1100 may be implanted relative to the carpal complex 6 and may then
articulate with the bearing 1206a. Therefore, no additional or
separate bearing components may be necessary and the bearing 1206a
may divide the bearing portion between the carpal implant 1100 and
a selected distal radial implant segment 1204.
As discussed above, the distal radial bearing 1206a may be
substantially molded to the distal radial implant segment 1204 to
allow for a fixation of the bearing components relative to the
distal radial segment 1204. Thus, the modular component may be
provided to allow for a minimal amount of portions that are
necessary to be implanted to form a substantially total wrist
arthroplasty.
With reference to FIGS. 40A and 40B, a distal radial bearing member
1206b which is a distal bearing member according to various
embodiments of the distal radial bearing member 1206 is
illustrated. The distal radial bearing member 1206b may be provided
with any of the selected distal radial implant segments 1204.
According to various embodiments, the distal radial implant 1206b
may be interconnected with the distal radial implant 1204b.
For example, the distal bearing implants 1206b may be substantially
molded or adhered to the distal radial implant 1204b similar to the
fixation of the distal radial bearing portion 1206a. Therefore,
various fixation mechanisms such as an adhesive, a screw, a locking
bar and the like may be provided. For example, a substantial
locking tab or projection 1350 may be provided to engage a rim or
section 1272 of the distal radial implant 1204b. The distal radial
bearing member 1206b also includes an articulation side 1352 that
defines a bearing surface 1354. The bearing surface 1354 may
articulate with a selected portion of the carpal complex 6 or a
selected portion of a carpal implant.
As discussed above, the articulation surface 1354 may articulate
with a bearing portion of a carpal implant 54 or any appropriate
bearing portion of a selected various embodiment of a carpal
implant. In addition, the articulation surface 1354 may articulate
with an articulating surface 1104 of the carpal implant 1100,
discussed above. Therefore, either the carpal implant 1100 alone
may articulate with the bearing member 1206b or a separate bearing
portion, which is interconnected with a carpal implant, may
articulate with the bearing surface 1354 of the bearing implant
1206b.
In addition, the bearing portion 1206b includes a flat or flat
extending portion 1356 that extends proximally from the
articulating side 1352. The flat portion 1356 may extend around the
flat portion 1274 of the distal radial implant 1204b. This may
allow for providing a portion of the bearing member around a
selected portion of the distal radial implant 1204b for selected
purposes. The extending or flat member 1356 may define a void 1358
which is operable to engage or receive a selected portion of the
flat portion 1274 of the distal radial implant 1204b.
The bearing portion 1206 according to various embodiments,
including the exemplary embodiments, 1206a and 1206b, may include
various dimensions, such as height 1360, a length, 1362 and a width
1364 or a plurality of dimensions. Therefore, the bearing component
1206 according to various embodiments may include a substantial
plurality number of unique and selectable dimensions for various
applications. Therefore, a user may select one of a plurality of
the varying components 1206 to meet selected requirements of a
particular patient. The user may select an implant from the kit
1600 (FIG. 44), an inventory or the like to provide an implant for
the requirements of a selected patient.
Therefore, it will be understood that the modular distal radial
implant 1200 may include a plurality of the stems 1202, a plurality
of the distal radial segments 1204, and a plurality of the distal
radial bearing components that may be selected and interconnected
in various and selected manners. This allows for the distal radial
implant 1200 to be provided as a substantially selectable implant
for various particular patients and uses by a user, such as
physician. The modular assembly may also allow for a substantial
intraoperative selection of the implant for a particular patient by
a physician or user. Thus, the implantation may proceed while
allowing for a substantially intraoperative customization of the
implant 1200 to the patient. In addition, the modular implant 1200
may be easily augmented or portions replaced during a revision
procedure due to the modular nature of the implant 1200.
As briefly discussed above, it will be understood that various
implants may be provided as substantially hemi-arthroplasty or
total wrist replacement. For example, the carpal implants, such as
the carpal implants 54 or the carpal implant 1100 may be provided
to interconnect with selected portions of the carpal complex 6 to
substantially articulate with a natural portion of the radius and
ulna. Therefore, a hemi-arthroplasty of the wrist joint or the
wrist area may be provided by only resurfacing or providing the
carpal implant. As discussed above, the carpal implant may include
a size to interconnect with a plurality of the bones of the carpal
complex 6 or may also replace a selected portion of the bones of
the carpal complex 6. Regardless, the carpal implant may be
provided to articulate with a natural portion of the radius.
Likewise, the distal radial implant according to various
embodiments may be provided to substantial articulate with a
natural portion of the carpal complex, as discussed above and
herein. Therefore, the distal radial implant may be provided to
articulate with a selected carpal implant or articulate with
selected portions of the carpal complex 6.
As discussed above, the various portions of the distal radial
implant may include a substantially modular distal radial implant
1200. The distal radial implant 1200 may include a plurality of
distal radial portions 1204 which may include a plurality of the
distal radial implant segments 1206 from which may be chosen one to
articulate with a natural portion of the carpal complex 6, a carpal
implant, or a combination thereof. Therefore, in the kit 1600 or a
supply, the selected implant may be chosen to include the distal
radial implant portion 1200 that is operable to interconnect or
articulate with a natural portion of the carpal complex 6 or the
carpal prosthetic. It will be understood that this may be done
substantially intraoperatively such that a user, such as a
physician, is able to chose from the kit 1600 or selecting the
portions that are required intraoperatively to allow for a
substantial customization regarding the selected patient.
With reference to FIG. 41, a distal radial implant 1400 according
to various embodiments is illustrated. The distal radial implant
1400 generally includes a stem 1402 and a distal radial segment
1404. It will be understood that the distal radial segment 1404 may
be substantially modular from the stem 1402, such as the modular
radial implant 1200. Therefore, the stem 1402 may be substantially
similar to the stem 1202 and the distal radial portion 1404 similar
to the distal radial portion 1204. Thus, the distal radial portion
1404 may be provided in the kit 1600 or supplied to be
interconnected with a selected one of the stems 1202 for formation
of the distal radial implant 1400. Regardless, it will be
understood that the distal radial implant 1400 may be substantially
provided as a single member for implantation and may also be
included in the kit 1600 of modular portions.
The distal radial segment 1404 generally includes a body portion
1406 that is interconnected with the stem 1402. As discussed above,
the body portion 1406 and the stem 1402 may be substantially formed
as a single member such that the distal radial portion 1404 is not
substantially separable from the stem 1402. Such a configuration
may be selected for various reasons, such as strength, materials,
and the like. Regardless, the distal radial portion 1404 may define
an articulation region extending distally from the body 1406.
The articulating side 1408 may include a first articulating fossa
or surface 1410 and a second articulating fossa or surface 1412.
The first articulating surface 1410 may substantially replicate a
scaphoid fossa for articulation with a scaphoid bone 8 after
implantation. The second articulation surface 1412 may be designed
to substantially articulate with the lunate bone 10 after
implantation. Therefore, the articulating surface 1408 of the
distal radial segment 1404 may be designed to substantially
replicate the natural articulating surfaces of the radius 2. This
may allow for a substantially natural articulation of the carpal
complex 6 relative to the radius 2 after a hemi-arthroplasty
regarding a resurfacing or replacement of the distal portion of the
radius 2.
The articulating surface 1408 may include a bearing portion that is
substantially fixed to the body 1406. Alternatively, the
articulating surface 1406 may include the substantially identical
material to the body 1406. For example, the body 1406 may be formed
of a selected metal or metal alloy and the articulating surface
1408 may be provided as a substantially polished surface to allow
for a selected articulation of the scaphoid 8 and the lunate 10
relative to the distal radial segment 1404.
The articulating surface 1408 may be defined substantially flat or
straight across the articulating surface 1408. Although the
articulating surface 1408 may include the depressions 1410 and 1412
to define the articulating surfaces, the articulating region 1408
may be substantially straight across its upper surface to as not to
substantially hinder movement of the carpal complex. Therefore, the
distal radial segment 1404 may include a height 1414, a selected
length 1416, and a width 1418.
As discussed above, it will be understood that the various
dimensions 1414-1418 may be substantially unique among a plurality
of the distal radial segments 1404 for selection by a user
substantially interoperatively or preoperatively. Regardless, this
allows the user to substantially select the portion for the distal
radial implant 1400, or a modular portion for the distal radial
implant 1200 to substantially suit a selected patient. Therefore,
the user may be able to select whether to provide a
hemi-arthroplasty or complete wrist replacement during the
operative procedure depending upon the state of the patient.
With reference to FIG. 42, a distal radial implant 1450 according
to various embodiments is illustrated. The distal radial implant
1450 may include portions that are substantially similar to the
distal radial implant 1400 and similar reference numerals are used
to reference like portions. Therefore, the distal radial implant
1450 may include the stem 1402 and a distal radial segment
1404.
As discussed above, the stem 1402 may be substantially modular
relative to the distal radial segment 1404 to provide for a modular
implantation of the distal radial implant 1450. In addition, a
plurality of the stems 1402 and the distal radial segments 1404 may
be provided for selection by a user. Alternatively, a plurality of
a fully integrated distal radial implant 1450 may be provided.
Therefore, the stem 1402 may be substantially integral with the
distal radial segment 1404 or may be provided separately therefrom
for interconnection during an operative procedure.
The articulating region 1408 of the distal radial implant 1450 may
include the first articulating portion 1410 and the second
articulating portion 1412. The first articulating portion 1410 may
be provided to articulate with the scaphoid 8. As discussed above,
the second articulating portion 1412 may be provided to articulate
with the lunate bone 10.
Depending upon a selected patient's anatomy, the ulnar side of the
distal radial segment 1404 may also include a recess 1452 for
articulation with the ulna 4. As will be understood by one skilled
in the art, the radius 2 may articulate with the ulna 4 during an
anatomical motion (such as pronation or supination) of the wrist or
arm portion and this may become damaged. Therefore, during an
operative procedure which may be required or replacement or a
resurfacing of the distal radial portion, the preparation of the
radius 2, such as a resection thereof, may require removing the
articulating region of the radius 2 that would generally articulate
with the ulna 4. Therefore, using the distal radial implant 1450,
including the recess 1452, may substantially allow an articulation
of the ulna with the implant 1450 connected to the radius 2, after
implantation of the distal radial implant 1450, in a substantially
natural manner. It will be understood that the recess 1452 may be
provided with any selected embodiment or in various embodiments of
the distal radial implant and the distal radial implant 1450 is
merely exemplary. For example the recess 1452 can be added to the
distal radial segment 1204c (FIGS. 36A and 36B).
In addition, the distal radial implant 1450 may include a curve or
curvilinear portion 1454 that may be provided to substantially
engage or hold a selected portion of the carpal complex 6 in a
selected location. The carpal complex 6, such as after a trauma,
may be unstable and require additional stabilization or retainment
in a selected anatomical orientation. Therefore, the curvilinear
portion 1454 may be provided on the distal radial implant 1450 for
holding the selected portion of the carpal complex 6 in a location.
It will be understood, again, that the curvilinear portion 1454 may
be provided on any selected implant for holding the carpal complex
6 in a selected location.
Therefore, it will be understood that the illustrated embodiments
are merely exemplary and not intended to limit the scope of any
exemplary embodiments. Regardless, providing an articulating
surfaces 1410 and 1412 that allows for substantially natural
articulation of the carpal complex 6 relative to the distal radial
implant 1400, 1450 may be selected to include further restricting
portions such as the curvilinear portion 1454. Similarly, a
resection of the radius 2 may allow or be selected to use the
recess 1452 to create an articulation region for the ulna.
With reference to FIG. 43, the distal radial implant 1450 is
illustrated exemplary implanted into a selected anatomy. The stem
1402 is implanted into the radius 2 to provide a fixation of the
distal radial implant 1450 relative to the radius 2. The distal
radial segment 1404 is positioned at an end, such as the distal end
of the radius 2 after preparing the radius 2 for the implantation.
The curvilinear portion 1454 is provided to retain a selected
portion of the anatomy, such as the scaphoid 8 relative to the
distal radial implant 1450. The first fossa 1410 is positioned to
articulate with the scaphoid 8 while the second fossa 1412 is
positioned to articulate with the lunate 10. In addition, the
depression 1452 is provided to allow an articulation of the distal
portion of the ulna 4 with the distal radial implant 1450.
Therefore, the implantation of the distal radial implant of 1450
may provide for articulation relative to the substantial natural or
anatomical carpal complex 6 rather than positioning a carpal
implant relative to the carpal complex 6. It will be understood
that the distal radial segment 1404 may also include a bearing
portion such as a polymer portion that may articulate with the bony
portions such as the scaphoid 8 and the lunate 10. Regardless, as
discussed above, the articulating surfaces 1410, 1412 may be
substantially polished metal portions to allow for a smooth
articulation of the natural portions of the carpal complex 6.
Therefore, it will be understood that each of the exemplary
embodiments may include portions that are substantially dissimilar
from the selected exemplary embodiments and may include
combinations of each of the various embodiments. Therefore, the
exemplary embodiments are not intended to limit the scope of the
following claims but merely are provided to exemplify the portions
thereof. Therefore, with reference to FIG. 44, the kit 1600 or
supply may include a plurality of the stem portion 1202a, 1202b
that each include a selected unique dimension, such as a length
1208a, 1208b, respectively. Furthermore, the kit 1600 may provide a
plurality of distal radial portions 1204a, 1204b, 1204c to provide
a distal radial portion according to any of the various
embodiments. Also, the kit 1600 may provide a plurality of distal
radial bearing members 1206a, 1206b that are operable to provide
any of the various embodiments discussed above. The kit may be used
by a user during procedure to select and assemble a distal radial
implant that is substantial customized to a selected patient.
Furthermore, the kit 1600 may provide a plurality of the carpal
implants, such as the carpal implant 54 according to various
embodiments, or the carpal implant 1100 and the bearing 56
according to various embodiments for selection by a user. In this
way, a user may select to provide a hemi-arthroplasty to provide a
prosthesis relative to the carpal complex 6 alone or relative to
the radius 2 alone. Alternatively, the user may select to provide a
substantially total wrist replacement that will provide a distal
radial implant and a carpal implant. While selecting either of the
total wrist arthroplasty or the hemi-arthroplasty, the user may
also select various portions that may be provided to allow for a
customized implant relative to the patient. The selection may occur
substantially intraoperative due to the kit which includes a
plurality of members which may be assembled to form the selected
prosthesis.
Accordingly, while the invention has been described in the
specification and illustrated in the drawings with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention as defined in the claims. In addition, many
modifications may be made to adapt a particular situation or
material to the teachings of the invention without departing from
the essential scope thereof. Therefore, it is intended that the
invention not be limited to the particular embodiment illustrated
by the drawings and described in the specification as the best mode
presently contemplated for carrying out this invention, but that
the invention will include any embodiments falling within the
foregoing description and the appended claims.
* * * * *
References